(1) Field of Invention
The present invention discloses ratchet gears, used in standard and pneumatic ratchet wrenches, which comprise adjustable jaws that are used to grip a fastener on at least four sides. The jaws, preferably traveling on rails or tracks, move inward and outward on a plane that is 90 degrees to the longitudinal axis of the gear body, through this sliding plane may be more or less than 90 degrees. A typical drive-means used in the prior art to drive adjustable socket jaws are horizontal thread-means used in the prior art to drive adjustable socket jaws are horizontal thread-means used in the prior art to drive adjustable socket jaws are horizontal thread-means, such as a double-threaded-stemmed knurled wheel, as in U.S. Pat. No. 4,864,901 and a single-threaded-stemmed wheel, as U.S. Pat. No. 4,798,108.
However, in the present invention, unique, angular cam surfaces integral to the jaws, contact novel, threaded, floating-cams which urge upon the jaws' cam surfaces. As a threaded rod or threaded-stem-disc is turned, the floating cams are driven in the direction of the gear's A longitudinal axis, not horizontally. Since the thread outside diameter may be wide enough to have a bore, a through-hole may be used in this structure and this feature minimized the need for "deep-well" type sockets. This unique structure prevents the gear from having to be too large, while allowing for fairly good jaw opening tang. One unfortunate drawback of the present invention is that it cannot be used as an independent socket, since the threaded-stem-disc, with or without through-hole, is necessarily located exactly where the socket range would need to be inserted.
(2) Description of Prior Art
Adjustable socket means have been known in prior art for several decades. One useful socket is found in U.S. Pat. No. 4,608,887 wherein a socket support body, comprising parallel slots in which parallel, cammed gripping surfaces slide while supported in an annular, rotatable flange. The drive means employed for driving the flange axially is a nut upon a threaded stem, located on the socket body. While effective, this socket requires a relatively wide girth and lengthy profile to operate.
In U.S. Pat. No. 4,385,534, externally fixed cam surfaces are used in conjunction with an adjusting screw means to bias inner, flexible jaws inward and outward upon a fastener. This socket comprises limitations not only due to the fact that the hard steel necessary for socket manufacture is not compatible with flexible steel, but the fact that the jaws are biased at an angle results in nonflush contact upon the sides of a fastener at sizes smaller than the maximum gripping aperture.
Less recent is an adjustable socket means that comprises two jaws pivoting upon a balljoint toward a fastener's sides, disclosed in U.S. Pat. No. 3,898,897. An impediment in this structure, as similar to the previous patent is the fact that since the jaws pivot from a central point, nonflush contact is also made on the sides of the fastener as the socket is adjusted.
Socket means that use linkage arms in conjunction with threaded adjusting means are found in U.S. Pat. Nos. 4,911,040 and 4,366,732. Though these structures allow for larger than average jaw-opening capacity, they require complex and bulky mechanical structures.
From the above discussed prior art it is evident that efforts have been made to produce an adjustable socket means which will securely grip a range of fasteners and include sufficient jaw-opening capacity so as to be of maximum usefulness. As well, efforts have been made to make such a socket means of relatively narrow girth and low-height profile and of few and reliable, strong parts having jaws that would open and close rapidly and tightly upon a fastener. It is an object of the present invention to meet the above requirements in an adjustable socket gear-means which may be used in standard and pneumatic ratchet wrenches presently in use.
It is another object to provide these ratchet gears with an optional hollow core or center along the gear's longitudinal axis, in order to provide the wrench user with a more useful wrench that may pass, for example, a threaded stem through itself.
Another object of this invention is to provide a threaded-stem-disc that is conveniently located on the top area of the ratchet wrench head and thus may be easily turned to adjust to the proper fastener size.